Fast 404 on 404 redirect from the htaccesss file [#1125158]

in boost_init run

    boost_fast404();

instead of

    drupal_not_found();
    return;

/**
 * Send out a fast 404 and exit.
 */
function boost_fast404() {
  global $base_path;
  if (!headers_sent()) {
    header($_SERVER['SERVER_PROTOCOL'] . ' 404 Not Found');
  }
  print '<html>';
  print '<head><title>' . t('404 Not Found') . '</title></head>';
  print '<body><h1>' . t('Not Found') . '</h1>';
  print '<p>' . t('The requested URL was not found on this server.') . '</p>';
  print '<p><a href="' . $base_path . '">' . t('Home') . '</a></p>';
  print '</body></html>';
  exit();
}